Africa now has more than half a million confirmed coronavirus cases.
The continent-wide total is more than 508,000, according to figures released today by the Africa Centres for Disease Control and Prevention, after South Africa recorded another day of more than 10,000 confirmed cases as a new global hot spot.
The true number of cases among Africa's 1.3 billion people is unknown as its 54 countries continue to face a serious shortage of testing materials for the virus.
"A tremendous problem, a real crisis of access," the World Health Organisation's Africa chief, Matshidiso Moeti, said last week.
So far most testing has been concentrated in capital cities, but infections in many cases have spread beyond them.
Covid-19 has already killed more people in Africa - 11,955 - than Ebola did in its deadliest outbreak from 2014 to 2016 in West Africa, the WHO said today.
"With more than a third of countries in Africa doubling their cases over the past month, the threat of Covid-19 overwhelming fragile health systems on the continent is escalating," Ms Moeti said today.
"So far the continent has avoided disaster," she added. If countries can continue to improve testing, tracing and isolating, "we can slow down the spread of the virus to a manageable level".
Africa's health systems are the most poorly funded and thinly staffed in the world, and more than 2,000 workers have already been infected by the virus, according to the WHO.
This week alone, some health workers in Nigeria, Zimbabwe, Congo and Sierra Leone have gone on strike or demonstrated for adequate protective gear or better pay.
The African continent has just 2.2 health workers - and 0.3 doctors - per 1,000 people, according to the WHO.
Experts have warned that even if badly needed supplies such as ventilators are provided, another challenge is having enough trained workers to operate them.
So far, WHO-organised shipments to African countries have included more than 3,000 oxygen concentrators, another key piece of equipment to help with breathing.
Africa reaches the half-a-million milestone as a growing number of its countries decide to reopen their skies to commercial flights, saying their economies are suffering.
Months of closed borders bought time to prepare for the pandemic but hurt the delivery of badly needed humanitarian aid.
